The present invention relates to a navigation apparatus mounted in a vehicle.
For example, Japanese Patent Unexamined Publication No. Hei. 8-16992 discloses a navigation apparatus mounted in a vehicle.
As shown in FIG. 4, this includes a receiver 1 for receiving an electric wave from a GPS satellite to output the position data of a present place, a reader 3 for reading map data from a map information storage medium 2 such as a CD-ROM, a buffer memory 4 for storing the map data, a display image memory 5 for extracting and copying a range required for displaying from the map data developed on the buffer memory 4, a display controller 7 for displaying the map data copied in the display image memory 5 on a display unit 6 such as a CRT or an LCD, and a controller 8, such as a micon, for controlling the whole system. The contents of the display image memory 5 are renewed in accordance with the change of the present position, and the display on the display unit 6 is also changed in accordance with this. Incidentally, an input unit 9, such as a keyboard, enabling a user, such as a driver, to perform various operations, such as setting of a start point and an arrival point or recording of traveling data, is connected to the controller 8.
Besides, in Japanese Patent Unexamined Publication No. Hei. 8-5721, another buffer memory 4a is prepared, and map data different from the buffer memory 4 is copied, so that, for example, an intersection approaching ahead can be displayed in detail (for example, enlargement) on the display unit 6.
Now, image data, such as the map data, copied in the buffer memory 4, 4a has a great amount of information, and in the so-called integral-type navigation apparatus in which the distance between the reader 3 as a transmitting side and the buffer memory 4, 4a as a receiving side is short, it is possible to copy and store the image data without much time delay, and a problem in display on the display unit 6 is hard to produce.
However, in the navigation apparatus in which the distance between the reader 3 and the buffer memory 4, 4a is long and transfer is made between them through serial communication, a renewal timing of image data is delayed, and there is a fear that an original display renewal is not made and a suitable display is not carried out. Particularly, in the case where an intersection is displayed in detail as in Japanese Patent Unexamined Publication No. Hei. 8-5721, there is a fear that a display is carried out after passing through the objective intersection.
According to the present invention, a navigation apparatus for a vehicle in which a transmitting side unit and a receiving side unit are installed at positions remote from, each other and both the units are connected to each other through a serial communication line, is characterized by comprising:
the transmitting side unit including at least a present position measuring unit for detecting a present position, a reader for reading transfer information from a map information storage medium, and a first controller for controlling a system and outputting display command information at a predetermined display timing; and
the receiving side unit including at least a second controller connected to the first controller through the serial communication line and receiving the display command information, buffer memories for storing the transfer information from the reader and for storing the transfer information related to a route selecting point with an enough time margin, a display image memory for extracting and copying a range required for displaying from the transfer information developed on the buffer memories, and a display controller for displaying a detailed image of the route selecting point based on the transfer information on a display unit by a command from the second controller when the second controller receives the display command information,
whereby the renewal timing of the display based on the transfer information is not delayed and an excellent display renewal can be made.
Besides, a navigation apparatus for a vehicle in which a transmitting side unit and a receiving side unit are installed at positions remote from each other and both the units are connected to each other through a serial communication line, is characterized by comprising:
the transmitting side unit including at least a present position measuring unit for detecting a present position, a reader for reading transfer information from a map information storage medium, and a first controller for controlling a system and outputting display command information at a predetermined display timing; and
the receiving side unit including at least a second controller connected to the first controller through the serial communication line and receiving the display command information, an input unit for carrying out route setting, buffer memories for storing the transfer information from the reader and for storing the transfer information related to a route selecting point based on the route setting with an enough time margin, a display image memory for extracting and copying a range required for displaying from the transfer information developed on the buffer memories, and a display controller for displaying a detailed image of the route selecting point based on the transfer information on a display unit by a command from the second controller when the second controller receives the display command information,
whereby the renewal timing of the display based on the transfer information is not delayed and an excellent display renewal can be made.
Besides, a navigation apparatus for a vehicle in which a transmitting side unit and a receiving side unit are installed at positions remote from each other and both the units are connected to each other through a serial communication line, is characterized by comprising:
the transmitting side unit including at least a present position measuring unit for detecting a present position, a reader for reading transfer information from a map information storage medium, and a first controller for controlling a system and receiving display command information; and
the receiving side unit including at least a second controller connected to the first controller through the serial communication line and outputting the display command information, an input unit for carrying out route setting, buffer memories for storing the transfer information from the reader and for storing the transfer information related to a route selecting point based on the route setting, a display image memory for extracting and copying a range required for displaying from the transfer information developed on the buffer memories, and a display controller for outputting the display command, information to the first controller to instruct the buffer memories to store the transfer information related to the route selecting point when the route setting by the input unit is completed, and for displaying a detailed image of the route selecting point based on the transfer information on a display unit at a display timing previously determined by the first controller or based on an operation signal from the input unit,
whereby the renewal timing of the display based on the transfer information is not delayed and an excellent display renewal can be made.
Besides, there is a feature that the transfer information read by the reader is map data in the vicinity of the present position, the transfer information stored in one of the buffer memories is image data for displaying the route selecting point by the detailed image, an identification number related to the route selecting point is given to the image data, and the display command information is a command including the identification number, whereby the image data intrinsic to the route selecting point can be previously transferred to the buffer memory, and even in the structure where the image data is transferred through serial communication with a low communication speed, the renewal timing is not delayed, and the display renewal can be made in accordance with the previously determined display timing.
Besides, there is a feature that the transmitting side unit is positioned at a place remote from a driver""s seat of the vehicle, and the receiving side unit is positioned in the inside of a meter unit installed in front of the driver s seat. Like this, even in the structure where the transmitting side unit and the receiving side unit are remote from each other, the renewal timing is not delayed, and the display renewal can be made in accordance with the previously determined display timing.
Besides, there is a feature that a controller prepared for controlling the meter unit is also used for the second controller, whereby cost reduction by the common use of parts can be realized.